Conventional standard-production ball and socket joints have two substantial disadvantages. First, the torques are impermissibly dispersed as a result of production despite annealing. Second, a more or less severe wear, which can greatly impair the driving properties of older vehicles and even cause failures, arises with increasing duration of operation. Simple measures for pre-loading, such as installing a rubber ring or a compression spring as a pre-loading element, have not proven themselves, because the pre-loading elements used yield under axial loads and are likely to cause play.
DE 1 450 064 A discloses a self-adjusting ball and socket joint, comprising a housing that has a socket part, which is provided with a ball-pin-head bearing seat, a ball pin having a ball head, which rests against the seat and the shaft of which extends out of the socket part, wherein a wall of the socket part is located at a distance from the ball head and is disposed on the side of the ball head opposite the seat, a self-exciting spindle drive device, which is disposed between the ball head and the wall in order to continuously load the head against the seat and which has a nut provided with an internal thread, the nut being screwed to a spindle provided with an external thread, and a spiral torsion spring, which is wrapped around the outside of the nut and which is connected to the nut at the inner end of the torsion spring, while the outer end of the torsion spring is connected to the spindle at a distance radially outward from the nut, wherein the torsional stress of the spring acts in a direction so as to unscrew the nut and the spindle in order to extend the spindle drive device. A flat thread or trapezoidal thread, for example, is used as the thread. A similar ball and socket joint is also known from GB 992 100 A.
In this ball and socket joint, the spindle is screwed into the nut so that the transmission formed by the spindle drive device is built relatively large in the axial direction. Furthermore, the friction between the spindle and the nut is relatively large for the threads used, which must be taken into account in the design of the spring.